Two date tools in one page: count the days between two dates (with an option to include the end date), or add and subtract days, weeks, months, and years from any starting date. Project deadlines, contract terms, pregnancy weeks, school breaks — any “how long” or “what date” question, answered live as you type.
Days between two dates
Add or subtract from a date
How it counts
The day counter computes true calendar days — it’s not fooled by 30 vs. 31-day months, leap years, or daylight saving shifts. The “include end date” checkbox matters for the everyday meaning of duration: October 18 to October 19 is 1 day apart but a 2-day trip. The add/subtract side is calendar-aware too: one month from January 31 lands on February 28, and one year from February 29, 2024 lands on February 28, 2025 — the same thing a bank or a court would compute.
Everyday examples
Deadlines: 45 days from today, for filings and permit windows. Contracts: a 90-day notice period from the date on the letter. Countdowns: days between today and a wedding, launch, or trip — check “include end date” to count the big day itself. Anniversaries: add 6 months to a start date for review and renewal dates. Weekends and holidays aren’t skipped — this counts pure calendar time; for business-day math, take the result as a starting point.
Built in-house in plain JavaScript and running entirely in your browser — no accounts, no tracking, and your dates never leave your device.